ST_Z
The ST_Z function takes a point as an input parameter and returns its Z coordinate.
If the specified point is null or empty, then null is returned.
Syntax
Parameters
- point
- A value of type ST_Point for which the Z coordinate is returned or modified.
Return types
DOUBLE
Examples
Example 1
This example
illustrates use of the ST_Z function. Geometries are created and inserted
into the SAMPLE_POINTS table.
SET CURRENT PATH = CURRENT PATH, db2gse;
CREATE TABLE sample_points (id INTEGER, geometry ST_Point);
INSERT INTO sample_points (id, geometry)
VALUES (1, ST_Point (2, 3, 32, 5, 1) );
INSERT INTO sample_points (id, geometry)
VALUES (2, ST_Point (4, 5, 20, 4, 1) );
INSERT INTO sample_points (id, geometry)
VALUES (3, ST_Point (3, 8, 23, 7, 1) );
Example 2
This example finds the Z
coordinates of the points in the table.
SELECT id, ST_Z (geometry) Z_COORD
FROM sample_points;
ID Z_COORD
---------- ----------------------
1 +3.20000000000000E+001
2 +2.00000000000000E+001
3 +2.30000000000000E+001